The maturation of the Web platform has given rise to sophisticated Web applications such as 3D visualization, audio and video software, and games. With that, efficiency and security of code on the Web has become more important than ever. WebAssembly is a portable low-level bytecode that addresses these requirements by offering a compact representation, efficient validation and compilation, and safe execution with low to no overhead. It has recently been made available in all major browsers. Rather than committing to a specific programming model, WebAssembly is an abstraction over modern hardware, making it independent of language, hardware, and platform and applicable far beyond just the Web. WebAssembly is the first mainstream language that has been designed with a formal semantics from the start, finally utilizing formal methods that have matured in programming language research over the last four decades.

1. Introduction

The Web began as a simple hypertext document network but has now become the most ubiquitous application platform ever, accessible across a vast array of operating systems and device types. By historical accident, JavaScript is the only natively supported programming language on the Web. Because of its ubiquity, rapid performance improvements in modern implementations, and perhaps through sheer necessity, it has become a compilation target for many other languages. Yet JavaScript has inconsistent performance and various other problems, especially as a compilation target.

WebAssembly (or "Wasm" for short) addresses the problem of safe, fast, portable low-level code on the Web. Previous attempts, from ActiveX to Native Client to asm.js, have fallen short of properties that such a low-level code format should have:

No entries found

Log in to Read the Full Article

Sign In

Sign in using your ACM Web Account username and password to access premium content if you are an ACM member, Communications subscriber or Digital Library subscriber.UsernamePasswordForgot Password?

Need Access?

Please select one of the options below for access to premium content and features.

Create a Web Account

If you are already an ACM member, Communications subscriber, or Digital Library subscriber, please set up a web account to access premium content on this site.

Join the ACM

Become a member to take full advantage of ACM's outstanding computing information resources, networking opportunities, and other benefits.

Subscribe to Communications of the ACM Magazine

Get full access to 50+ years of CACM content and receive the print version of the magazine monthly.

Purchase the Article

Non-members can purchase this article or a copy of the magazine in which it appears.